Hi everybody, glad to join you all in this forum.
I hope my post is in the correct section, if not let me know.
TL;DR:
Want to make wireless battery powered sensor for my home communicating with a raspberry pi 4B.
RFM modules? please help! I have no idea what I'm doing ^^
Some background before my question:
I have no background whatsoever in coding (except some minor interest over the last few years), any hardware or electronics or anything that has to do with sensors and signals. I started learning python a month or two ago, then recently discovered raspberry pi with which I was able to set up a local server. What I would like to try next is using this raspberry pi (4B) to communicate with sensors spread in my house measuring temperature and humidity. I've looked over the internet over the last few days and keep finding "better" ways to do it, so I hope to finally find out how I should proceed exactly
My initial plan was using ESP32 linked to a DHT22 sensor sending data to my server through wifi. As I want to be able to move them around and place them whereever I want I wanted to use battery power. I then realised battery life of a ESP32 (using a 2-3000 mA 3.7V battery) is usually not so great. I then discovered LoRa networks and ended up with the idea of using a SeeedStudio WM1302 LoRaWAN HAT for Raspberry Pi (connected to the pi obviously) getting data from a microprocessor (probably raspberry pi pico) linked to my sensor and a RFM95 module.
However, I finally ended up on this forum where it was mentioned RFM95 is usually for very long range and RFM69 should do the job just fine.
So now, I am completely confused. So here are my questions, any advice concerning my project is also welcome:
- Is the WM1302 LoRaWAN HAT "compatible" with RFM69 (and is it with RFM95)? I suppose they should use a similar frequency?
- Are modules like the RFM69 able to both receive and transmit data or do I need special versions to transmit/receive signal?
- I saw there are several RFM69 versions (C,CW,HW,HCW), what are the differences exactly? I found this answer (
https://lowpowerlab.com/forum/rf-range-antennas-rfm69-library/difference-between-rfm69-w-and-cw-(or-hw-and-hcw)/) which helps a bit but leads to the questions: If I understand correctly dBm correlates to the power thus the range of the module? Also, there is a mention of different pin-out, how does this affect compatibility with a pico microprocessor for example?
- Are all the modules mentioned programable with python?
- I saw many mentions of arduino in my search, is it perfectly possible to have a remote sensor using arduino parts communicating with my raspberry pi 4B? Also, is any RFM module compatible with both arduino/raspberry etc or could there be some issues when I try to combine them into a remote sensor?
- Finally, I currently already have the raspberry pi 4B, the ESP32 (with integrated 3.7V battery power supply) and a DHT22 sensor (I ordered the last two before learning about LoRa). Any suggestions on how you would tackle making wireless battery-powered sensors (with or without any of the components mentiond) are always welcome!
Thanks for taking the time to go through my questions and feel free to redirect me to sources that have the answers or more info on basic concepts that might help me.